小鼠主动脉弓狭窄术左室肥厚模型的评价研究

Evaluation of left ventricular hypertrophy model induced by transverse aortic constriction in mice

目的探讨高频超声多普勒检测主动脉弓狭窄术(TAC)主动脉弓血流速度时间积分,早期评估左室肥厚(LVH)模型建立的可靠性。方法采用TAC小鼠LVH模型,多普勒超声检查主动脉的血液流速度时间积分,结合心动超声影像,左室质量指数,病理组织学方法检查,评价心脏功能。结果小鼠行TAC术后3 d,TAC组主动脉弓处血流速度峰值较假手术(Sham)组明显加快(P<0.01),结扎处血管直径TAC组较Sham组狭窄,具有统计学意义(P<0.01),提示TAC手术早期构建LVH模型成功。小鼠行TAC术后2周主动脉结扎处血流速度积分与左心室射血分数(LVEF)成负相关(r=0.901,P<0.01)。小鼠LVH模型TAC术后2周、4周后,心脏超声检查显示,收缩末期左室室间隔厚度,LVEF,短轴缩短率与Sham组有明显差异(P<0.01)。TAC术后2周、4周后小鼠心脏体积明显较Sham组增大,病理组织学检查,心肌组织发生不同程度的变化。结论应用高频多普勒超声检测TAC术后小鼠主动脉弓狭窄处的血流速度时间积分,可以评估LVH模型建立的可靠性。

Objective To investigate the degree of aortic arch stenosis and blood flow velocity detected by high-frequency ultrasound Doppler in mice after transverse aortic constriction(TAC)and to investigate the reliability of left ventricular hypertrophy(LVH)of TAC in early assess the stenosis.Methods The LVH model of TAC mice was used,and the blood flow velocity time integral of aorta was examined by high frequency Doppler echocardiography,combined with echocardiography,left ventricular mass index,and histopathological examination to evaluate the cardiac function.Results At 3 days after TAC,the blood flow velocity was significantly faster than that in Sham group,and the vessel diameter at the ligation site in TAC group was narrower than that in Sham group,with statistical significance,suggesting that the LVH model was successfully constructed in the early stage of TAC surgery.In TAC-2w the flow velocity score at aortic ligation was negatively correlated with left ventricular ejection fraction(%)(r=0.901,P<0.01).There were significant differences in left ventricular mass index at TAC-2w,TAC-4w compared with those in Sham group(P<0.01).Conclusion Blood flow velocity in mice after TAC could early evaluate the reliability of aortic arch stenosis induced LVH model,and contribute to the early judgment of successful modeling of LVH.